Due to effective treatment, persons living with HIV and accessing care (PLWHC) in the United States (US) now have a life expectancy approaching the general population. In the general population, the population bubble caused by the post-WWII Baby Boom has been referred to as the Silver Tsunami. The goal of this project is to fill a vital gap for a more detailed, data-based projection of the imminent PLWHC Silver Tsunami to better inform allocation of resources in governmental and private healthcare systems and to identify targets for savings. Taking into account factors that affect the age distribution of PLWHC in the US, we will use simulation models to project the age distribution through 2030 to answer the question: What does the projected age distribution of PLWHC in the US look like? To be useful, data need to be disaggregated by important demographic (sex and race) and geographical characteristics. HIV infection has been shown to increase the risk of insulin resistance, chronic kidney disease, myocardial infarction, end-stage renal disease, and cancer. Incorporating multimorbidity and polypharmacy into the projected age distribution will answer: What is the projected burden of multimorbidity and polypharmacy in adults aging with HIV? Information derived by a careful, data-based analysis that includes the burden of multimorbidity and polypharmacy in PLWHC will have many uses. We propose to focus on the important issue of healthcare costs as it is likely that costs will be compounded in adults aging with HIV as compared to those without HIV. By investigating the question How much will it cost to care for adults aging with HIV? health systems and state and federal budgets can begin to prepare for both HIV-related and non-HIV-related costs and identify targets for potential cost savings. We have assembled a world-class collaboration that combines high-quality longitudinal data, epidemiological expertise, the scientific leaders of the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD), and the leaders in modeling of HIV disease and healthcare costs from the Cost-Effectiveness of Preventing AIDS Complications (CEPAC) team to achieve the following aims: AIM 1: To fill the gap in knowledge by projecting age-specific proportions of PLWHC in the US through 2030, with estimates tailored to important demographic and geographic sub-groups. AIM 2: To project the burden of multimorbidity and polypharmacy among PLWHC in the US through 2030. AIM 3: To project the annual costs of non-HIV-related healthcare for PLWHC in the US through 2030. The proposed aims align well with the research priorities of the 2016 Trans-NIH Plan for HIV-Related Research and the NIH HIV/AIDS Research Priorities and Guidelines for Determining AIDS Funding. Findings will provide key HIV epidemiologic and health services data that are necessary for guiding research priorities, increasing awareness of multimorbidity and polypharmacy in clinical management, and informing health systems resource allocations.